Buffalo Technology has become the latest vendor to announce a USB hard drive featuring built-in, hardware-backed encryption. Almost as interesting is that is costs almost the same as the same drive without security.

Launched last year, the MiniStation range was intended to be the company's take on the idea of hauling around a 2.5-inch portable hard drive inside a "rugged" case. Capacities are currently 160GB and 320GB, with a USB 2.0 interface, a wrap-around data cable, and Memeo's backup software-for-one.

The new drive, dubbed 'Pro', is identical to this spec in every respect bar one -- accessing the data requires entering a password. No client software is necessary to enable the 128-bit AES encryption because it is built into the drive at hardware level to operate transparently.

The user is unaware that encryption is even being used beyond the password entry requirement. Detach the unit and the data is re-encrypted automatically without, apparently, any noticeable performance penalty.

"The need to securely transport large amounts of confidential company data is continuing to rise, with businesses now requiring more capacity than a USB flash drive can offer," commented Buffalo's Kevin Vine in the official release. "The Pro addresses this need and offers an even more secure option for portable storage."

Such encryption normally attracts a price premium, but the MiniStation Pro has apparently managed to almost abolish this issue. The new drives are expected to cost around £76 (US$152) for the 160GB version and £136 for the 320GB model, including VAT, a modest hike on buying the same drive without the encryption. A bog-standard 160GB MiniStation has a street price of around £59 with VAT, only £17 pounds less than the Pro in the same capacity.

The MiniStation Pro also comes with mobile versions of Mozilla Firefox and the Thunderbird email program.

Rivals to the drive are still few and far between, though a clutch are expected through 2008. In time, the encryption will become a standard feature, even for low-end drives, as it is slowly becoming in the USB storage segment. The external version of Stonewood's specialist Eclypt drive is considerably more expensive, but adds extra layers of tamper-proofing as well as 256-bit AES encryption, and management.